Patent GB-730670-A (GB)
Title: A process for producing high molecular weight condensation products from polyepoxides and sulphur-containing compounds
IPC: C08G59/40
Filed: 1952-11-17
Abstract: Sulphur-containing polymers are produced by reacting a compound containing at least two epoxy groups with H2S or with a compound containing at least two mercaptan groups.  Suitable polyepoxy compounds are diglycidyl ether, diglycidyl thioether, polymerized allyl glycidyl ether, or glycidyl ethers prepared from epichlorhydrin or 2,3-epoxy-propanol-1 and a polyhydric alcohol or phenol as described in Specifications 681,001 and 681,991.  When using H2S the reaction is preferably catalysed with alkali. Suitable polymercapto compounds are alkane or alkene dithiols with 2-18 carbon atoms, heterocyclic dithiols with 7-20 carbon atoms, dithiol derivatives of aliphatic monoethers or monothio ethers, compounds of the formula HSRXRSH in which X represents a furane or pyrane nucleus which may be hydrogenated and R a divalent aliphatic hydrocarbon group, polysulphides with terminal mercaptan groups, prepared, e.g. according to the process of U.S.A. Specification 2,466,963, by treating a polysulphide, which may be prepared from di-(2-chlorethyl) acetal, trichloropropane, and sodium polysulphide, with sodium hydrosulphide or water and sodium sulphite or products prepared according to the invention from polyepoxy compounds and an excess of H2S.  The molecular weight of the product and the nature of the residual group may be controlled by varying the proportions of the reactants.  For high molecular weight products, e.g. for fibres or films roughly equivalent amounts should be used.  With H2S reaction temperatures may vary from -15 DEG  C. to 150 DEG  C. but are preferably low to increase the solubility of the H2S.  With polymercaptans temperatures vary from 15-100 DEG  C.  The reaction may be effected in solution, and if desired in an inert atmosphere. Minor quantities of compounds containing only one epoxy or mercaptan group, e.g. epichlorhydrin, 2,3-epoxypropoxybenzene, ethyl mercaptan or benzyl mercaptan may be included in the reaction mixture.  The products are viscous liquids or fusible solids which may be cross-linked with e.g. sodium or potassium hydroxide, phenolate or methylate, triethylamine, ethylene diamine, diethylamine, 2,4,6-tri(dimethylaminomethyl) - phenol, diethylene triamine, triethylene tetramine, pyridine, piperidine, dicyandiamide or melamine, or by lead dioxide or organic peroxides.  Other cross-linking agents are diisocyanates, dialdehydes, e.g. glyoxal polybasic acids, e.g. phthalic acid, amine- or amide-aldehyde resins. The cross-linking may be effected during or after the initial reaction.  The products may be used for moulding, casting, coating, impregnating or adhesion.  Other film-forming materials, e.g. drying oils, cellulose derivatives, vinyl polymers may be mixed with the products.  Solvents and/or diluents may be added. Low molecular weight products may be treated to increase their molecular weight, e.g. according to the invention or with lead dioxide, or organic peroxide to make them suitable for fibres or films.  The products may be after-treated with monofunctional agents such as monocarboxylic acids, e.g. acetic acid or drying oil fatty acids.  In the examples (1) hydrogen sulphide was bubbled through a toluene solution of a glycidyl ether of bisphenol in presence of sodium methylate.  A film-forming resinous product was obtained.  Mixed with lead dioxide it yielded a potting composition.  Dissolved in cyclohexanone and mixed with di-(isocyanatophenyl)methane it yields a film-forming composition. It yielded coating compositions when dissolved in cyclohexanone and mixed with a butyl acetate solution of nitrocellulose or with a cyclohexanone solution of a vinyl chloride/vinyl acetate copolymer.  Satisfactory coatings were also produced from a solution of the resinous product and of urea-formaldehyde resin in a mixture of xylene, cyclohexanone and butanol.  (2) The resinous product of example (1) was esterified with acetic acid and with phthalic acid.  (3) A glycidyl ether of bisphenol was reacted with 1,5-pentanedithiol.  The condensate was hardened with 2,4,6-tri(dimethylaminomethyl)-phenol.  Similar condensates were prepared using 1,4-butanedithiol, 1,4-cyclohexanedithiol, di(3-mercaptopropyl)sulphide or di-(3-mercaptopropyl)sulphoxide. (5) Diglycidyl sulphide was reacted with H2S or with 1,5-pentanedithiol.  (5) Diglycidyl ether was reacted with H2S or with 1,5-pentanedithiol.  (6) A glycidyl ether of bisphenol mixed with a polymer of allyl glycidyl ether was reacted with H2S.  The polymerized allyl glycidyl ether was also reacted alone with 1,5-pentanedithiol or other dimercaptan to give a hardenable product.  (7) A glycidyl ether of glycerol was p  reacted with H2S.  Mixed with lead dioxide the product yielded a potting composition.  The H2S was replaced by 1,5-pentanedithiol and a product hardenable with 2,4,6 - tri - (dimethylaminomethyl)phenol was obtained.  (8) Glycidyl ether of bisphenol was reacted with H2S.  In examples (9), (10) and (11) a number of similar reactions are described employing a polymeric mercaptan obtainable under the Registered Trade Mark Thiokol and prepared for example according to the process described in U.S.A. Specification 2,466,963.  In one of them a glycidyl ether of bis-phenol mixed with allyl glycidyl ether, Thiokol and 2,4,6-tri-(dimethylaminomethyl)phenol was hardened as an adhesive layer between blocks of phenolformaldehyde laminates.